I thank you for not diverting your hash rate to BCH and doing an overwhelming attack on the BCH network that would cost BCH investors unaware of this real risk a small fortune.

It would clearly be trivial to rob anyone who was daft enough to put money into the BCH network these days now that sort of power has been wielded.

For instance someone controlling that sort of hashing power (6+Exahashes) could easily pull off a 51% attack on the insecure BCH network with a mere 4 Exahashes protecting it.

A simple deposit of say 1000 BCH (Today's value of around $ 600k) to an exchange, wait for 2-3 blocks of deposit time, exchange to BTC, withdraw the BTC (Around 85BTC at writing), now fork the BCH chain to reissue the last 5-6 BCH blocks (perhaps taking 1-2 hours) merely omitting your original BCH transaction and ta-dah you have that 1000BCH back to double spend on another exchange and gained $ 600k of real value. If people were still in la-la land believing BCH was secure and continued using it you could simply repeat-rinse until they got the message.

Yes that exchange would bar you from depositing BCH again but nothing stopping others opening accounts and doing the same since the BCH network is simply pwned at this stage. (I have no idea how a decentralised exchange could even offer any protection out there for BCH holders at the moment other than merely dropping the coin).

The fact that you haven't done this and making meagre profits mining (6ExaHash/54Exahash = 11% of the block rewards = $ 11% of $ 12m per day = $ 1m per day) even though you could generate probably $ 1m+ in an hour of attacking BCH shows you believe in BTC and have ethics.

I'm not confident other miners would be so selfless so perhaps this is more a PSA that if you own any BCH this is a very real risk to be aware of as the attack would happen quickly.